CN108633118B - Method of operating a transistor, circuit comprising a protection driver and integrated circuit - Google Patents

Method of operating a transistor, circuit comprising a protection driver and integrated circuit Download PDF

Info

Publication number
CN108633118B
CN108633118B CN201810218365.XA CN201810218365A CN108633118B CN 108633118 B CN108633118 B CN 108633118B CN 201810218365 A CN201810218365 A CN 201810218365A CN 108633118 B CN108633118 B CN 108633118B
Authority
CN
China
Prior art keywords
voltage
transistor
igbt
circuit
coupled
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201810218365.XA
Other languages
Chinese (zh)
Other versions
CN108633118A (en
Inventor
彼得·布雷德迈尔
约格·塞雷索
托马斯·基默
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Infineon Technologies AG
Original Assignee
Infineon Technologies AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Infineon Technologies AG filed Critical Infineon Technologies AG
Publication of CN108633118A publication Critical patent/CN108633118A/en
Application granted granted Critical
Publication of CN108633118B publication Critical patent/CN108633118B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/06—Control, e.g. of temperature, of power
    • H05B6/062—Control, e.g. of temperature, of power for cooking plates or the like
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
    • H01L27/0203—Particular design considerations for integrated circuits
    • H01L27/0248—Particular design considerations for integrated circuits for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection
    • H01L27/0251—Particular design considerations for integrated circuits for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection for MOS devices
    • H01L27/0255—Particular design considerations for integrated circuits for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection for MOS devices using diodes as protective elements
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage
    • H03K17/081—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit
    • H03K17/0814—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit by measures taken in the output circuit
    • H03K17/08148—Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit by measures taken in the output circuit in composite switches
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage
    • H03K17/082—Modifications for protecting switching circuit against overcurrent or overvoltage by feedback from the output to the control circuit
    • H03K17/0828—Modifications for protecting switching circuit against overcurrent or overvoltage by feedback from the output to the control circuit in composite switches
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
    • H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
    • H03K17/567—Circuits characterised by the use of more than one type of semiconductor device, e.g. BIMOS, composite devices such as IGBT
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
    • H01L27/0203—Particular design considerations for integrated circuits
    • H01L27/0248—Particular design considerations for integrated circuits for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection
    • H01L27/0251—Particular design considerations for integrated circuits for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection for MOS devices
    • H01L27/0288—Particular design considerations for integrated circuits for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection for MOS devices using passive elements as protective elements, e.g. resistors, capacitors, inductors, spark-gaps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof  ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/70—Bipolar devices
    • H01L29/72—Transistor-type devices, i.e. able to continuously respond to applied control signals
    • H01L29/739—Transistor-type devices, i.e. able to continuously respond to applied control signals controlled by field-effect, e.g. bipolar static induction transistors [BSIT]
    • H01L29/7393—Insulated gate bipolar mode transistors, i.e. IGBT; IGT; COMFET
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/08—Modifications for protecting switching circuit against overcurrent or overvoltage
    • H03K2017/0806—Modifications for protecting switching circuit against overcurrent or overvoltage against excessive temperature
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K2217/00—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
    • H03K2217/0027—Measuring means of, e.g. currents through or voltages across the switch

Abstract

A method of operating a transistor, a circuit including a protection driver, and an integrated circuit are disclosed. The method comprises the following steps: turning on and off the transistor based on the control signal; monitoring a voltage of a collector node of the transistor; detecting whether a voltage of a collector node of the transistor is greater than a first threshold; and adjusting a voltage across a load path of the transistor to a first target voltage after detecting that the voltage of the collector node of the transistor is greater than a first threshold.

Description

Method of operating a transistor, circuit comprising a protection driver and integrated circuit
Technical Field
The present invention relates generally to electronic circuits, and in particular embodiments, to transistors with integrated active protection.
Background
Transistor devices are widely used as electronic switches in a variety of different applications, such as industrial, automotive or consumer applications. These applications may include power conversion, motor drive, induction heating or lighting applications, and the like. In many of these applications, the driver turns transistor devices on and off based on a PWM (pulse width modulation) signal. The frequency of the PWM signal may depend on the type of application and/or the operating state of the respective application. For example, in a heating application where a transistor device may be used to drive a heating resistor, the frequency of the PWM signal may be tens of Hz; in lighting applications where transistor devices may be used to drive a lamp, such as a Light Emitting Diode (LED), the frequency of the PWM signal may be several hundred hertz; in motor vehicle applications where transistor devices may be used to drive the solenoid valves, the frequency of the PWM signal may be several kilohertz (kHz); in motor drive applications, where transistor devices may be used to drive a brushed DC motor, the frequency of the PWM signal may be tens of kHz; and in power conversion applications where transistor devices may be used to drive inductive loads (chokes), the frequency of the PWM signal may be tens to hundreds of kHz.
Transistor devices can be implemented with different technologies. The choice of transistor type can be important since each transistor technology typically provides different tradeoffs between different performance levels, size, and cost. For example, Insulated Gate Bipolar Transistors (IGBTs) are typically optimized for high efficiency and switching. IGBTs are also typically capable of operating at very high voltages, with breakdown voltages of up to 1kV, 1.2kV, or higher.
Technologies such as IGBTs may be suitable for applications such as Induction Heating (IH) cookware. IH cookware is very popular, in part because of its energy efficiency. To achieve high energy efficiency, IH cookware may use a resonant converter topology due to soft switching losses and lower EMI spectrum.
Disclosure of Invention
According to one embodiment, a method of operating a transistor includes: turning on and off the transistor based on the control signal; monitoring a voltage of a collector node of the transistor; detecting whether a voltage of a collector node of the transistor is greater than a first threshold; and adjusting a voltage across a load path of the transistor to a first target voltage after detecting that a voltage of a collector node of the transistor is greater than a first threshold.
Drawings
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates an exemplary IH cookware system according to an embodiment of the invention;
FIG. 2a shows a protected IGBT in an IH cookware subsystem according to an embodiment of the invention;
FIG. 2b shows a high level view of a protection driver according to an embodiment of the invention;
figure 2c shows a protection driver with a diagram of a current limiter circuit according to an embodiment of the invention;
FIG. 2d shows waveforms of an IH cookware subsystem according to an embodiment of the invention;
fig. 2e and 2f show V of the load path across the IGBT 202 with two different AC input voltages according to an embodiment of the inventionceAnd the waveform of the current;
fig. 2g shows a protection driver with a diagram of an overvoltage protection circuit according to an embodiment of the invention;
FIG. 2h shows V of an IGBT during an overvoltage condition according to an embodiment of the present inventionceA current across a load path of the IGBT and a voltage of a gate of the IGBT;
fig. 2i shows a protected IGBT with a diagram of a diagnostic circuit according to an embodiment of the invention;
FIG. 2j shows a table with voltage ranges and fault types according to an embodiment of the invention;
fig. 2k shows a flow chart of an embodiment method of operating an IGBT transistor;
FIG. 3 illustrates a protection driver having a diagram of a current limiter circuit according to another embodiment of the present invention;
FIG. 4 illustrates a protection driver having a diagram of an overvoltage protection circuit in accordance with another embodiment of the present invention;
fig. 5a shows a protection driver with a diagram of an overvoltage protection circuit 541 according to a further embodiment of the invention;
FIG. 5b shows the V of the IGBT during an overvoltage condition according to an embodiment of the present inventionceA current across a load path of the IGBT and a voltage of a gate of the IGBT;
FIGS. 5c and 5d show a flow chart of an embodiment method of operating an overvoltage protection circuit;
FIG. 6 shows a protected IGBT in an IH cookware subsystem according to another embodiment of the invention;
FIG. 7a shows a protection driver in an IH cookware subsystem according to an embodiment of the invention;
fig. 7b and 7c show a single pulse waveform of the current flowing through the diode before and after, respectively, removing the cooking vessel from the PCB arrangement of the simulated cooking surface, according to an embodiment of the invention; and
fig. 7d shows waveforms of current flowing through the diode before and after the cooking container is removed from the cooking surface according to another embodiment of the present invention.
Corresponding numerals and symbols in the various drawings generally refer to corresponding parts unless otherwise indicated. The drawings are drawn to clearly illustrate relevant aspects of the preferred embodiments and are not necessarily drawn to scale. To more clearly illustrate certain embodiments, letters indicating changes in the same structure, material, or process steps may follow the figure number.
Detailed Description
The making and using of the presently preferred embodiments are discussed in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the invention.
The present invention will be described with respect to preferred embodiments in a specific context, IGBTs with integrated active protection in various implementations and systems. Embodiments of the present invention may be used with other implementations of single-ended parallel resonant topologies, other types of transistors, alternative implementations, and other systems (e.g., microwave ovens and rice cookers).
In an embodiment of the present invention, the IGBT is integrated with an overvoltage protection circuit, a current limiter circuit, and an over-temperature sensor. The integrated temperature sensor is capable of monitoring the junction temperature of the IGBT, while the integrated current limiter circuit and overvoltage protection circuit are capable of protecting the IGBT from overcurrent or overvoltage conditions. The current limiter circuit may be implemented without a sense resistor in the gate driver loop. The overvoltage protection circuit can be implemented by having a regulation loop that regulates the voltage across the load path of the IGBT when an overvoltage condition is detected. Some embodiments may regulate the voltage across the load path of the IGBT to a fixed target voltage after detecting the overvoltage condition. Other embodiments may dynamically adjust the voltage across the load path of the IGBT after an overvoltage condition is detected.
IH cookware is a system that heats a load (typically a cooking vessel) by providing an AC current through an induction coil. The induction coil induces eddy currents in the cooking vessel, which cause the cooking vessel to heat up. Generally, a cooking container is made using a material such as iron that generates eddy current and heat from a magnetic field. The frequency and duty cycle of the AC current may be adjusted and optimized to generate heat on a particular type of material. The efficiency of the generation of the AC current can be optimized by using a resonant tank (resonance tank) tuned to a specific resonant frequency.
FIG. 1 illustrates an exemplary IH cookware system 100 according to an embodiment of the present invention. The IH cooker system 100 includes an AC power source 124, a bridge rectifier 118, a resonant tank 105, a load 144, the IGBT 102, external temperature sensors 110 and 112, a gate driver 120, controllers 126 and 134, a capacitor 108, and user interfaces 142 and 140. The resonant tank 105 includes a resonant inductor 106 and a resonant capacitor 104. The controller 126 includes an analog-to-digital converter (ADC)132, a comparator block 130, an output block 128, and a protection control block 127.
During normal operation, the bridge rectifier 118 rectifies the voltage provided by the AC power source 124. When the IGBT 102 is turned on, current may flow from the node VRECT + through the resonant inductor 106 and through the load path of the IGBT 102. When the IGBT 102 is turned off, the current flowing through the resonant inductor 106 flows into the resonant capacitor 104 until the current flowing through the resonant inductor 106 reaches zero. When the current through the resonant inductor reaches zero, the voltage across the resonant capacitor 104 is at its maximum value within its cycle. After the current flowing through the resonant inductor reaches zero, the voltage across the resonant capacitor 104 causes current to flow through the resonant inductor 106 in the opposite direction, thereby discharging the resonant capacitor 104. Such current may charge the capacitor 108 and may be recirculated through the diode of the IGBT, which may reduce the voltage across the load path of the IGBT 102. After the voltage across the load path of the IGBT 102 drops to, for example, zero volts, the IGBT 102 may be turned on with Zero Voltage Switching (ZVS), repeating the sequence.
When the voltage of node VRECT + is high, the current flowing through the load path of IGBT 102 may reach a high peak value. The peak value of the current flowing through the load path of the IGBT 102 when the IGBT 102 is turned on may determine the peak voltage of the resonance capacitor 104 when the IGBT 102 is turned off. Thus, controlling the maximum peak current flowing through the load path of the IGBT 102 when the IGBT 102 is on may also control the maximum collector-emitter voltage (V) of the IGBT 102 when the IGBT 102 is offce). Clamping the peak current flowing through the IGBT 102 when the IGBT 102 is on at a voltage that causes the IGBT 102 to be exposed to V below the breakdown voltage of the IGBT 102 when the IGBT 102 is offceCan prevent damage to the IGBT 102. The protection control block 127 may monitor the current flowing through the load path of the IGBT 102 by measuring the voltage at the terminals of the resistor 122 using the ADC 132, monitor the voltage of VRECT + by using the ADC 132, determine a safe maximum value for the peak current flowing through the IGBT 102, and turn off the IGBT 102 if the safe maximum value for the peak current is exceeded.
Power delivery to the load 144 may be controlled, for example, to regulate the temperature of the load 144. The power delivered to the load 144 is based on the average voltage at node VRECT + and the average current through the load path of the IGBT 102. The voltage of node VRECT + may vary based on the voltage of AC power source 124. The controller 126 may calculate the delivered power by, for example, multiplying the average current flowing through the load path of the IGBT 102 by the average voltage of the node VRECT +, and may adjust the on-time of the IGBT 102 to achieve a particular power delivery level.
The controller 126 may be configured to adjust the temperature of the load 144 to a particular target load temperature. For example, the controller 126 may monitor the temperature of the load via the ADC 132 using the temperature sensor 110 and adjust the on-time of the IGBT 102 to reach the target load temperature. Alternatively, the controller 126 may operate open loop to adjust the duration that the IGBT 102 conducts based on the target load temperature without monitoring the temperature sensor 110. The controller 126 may control the state of the IGBT 102 with the output block 128 via the gate driver 120. Other implementations are possible.
Controller 134 may provide information to a user via user interface 140, such as a current temperature of load 144, and may receive information from a user via user interface 142, such as a target load temperature. The target load temperature may be provided to the controller 126 such that the controller 126 adjusts the temperature of the load 144 to reach the target load temperature.
In general, transistors, and in particular IGBTs, may be damaged in the event of an overcurrent, overvoltage, or overtemperature condition. To prevent system failure, the IH cooker system 100 may implement various protection mechanisms. For example, the microcontroller 126 may be configured to monitor the external temperature sensors 110 and 112 and reduce or stop power delivery when a dangerous temperature is reached at the load 144 or the IGBT 102, respectively. Back-to-back zener diodes (not shown) may be placed between the base and collector terminals of the IGBT 102 to clamp the voltage between the base and collector terminals of the IGBT 102, thereby clamping the V of the IGBT 102 during an overvoltage conditionce. V of IGBT 102ceClamping to a voltage below the breakdown voltage of the IGBT 102 can prevent damage to the IGBT 102.
IGBT breakdown voltages tend to have positive thermal coefficients. In other words, the hotter the junction temperature of the IGBT, the higher the breakdown voltage and, therefore, the higher the voltage across the load path of the IGBT 102 that can be tolerated. Thus, the overvoltage protection circuit may be designed to dynamically vary the clamping voltage based on the temperature of the IGBT 102 to optimize system performance. The protection control block 127 may measure V of the IGBT 102 via the ADC 132ceAnd can be at VceControlling the gate of the IGBT 102 via the gate driver 120 to adjust V when the voltage exceeds a predetermined thresholdceA voltage.
The controller 126 may be implemented using an external controller. Since the external temperature sensor may not be able to detect rapid internal temperature changes due to long thermal time constants, the controller 126 may be configured to actively limit power delivery to avoid system failure or damage to the IGBTs 102 due to over-temperature conditions. Similarly, the controller 126 may be configured to activate the overvoltage clamping circuit when an overvoltage condition is detected. The controller 126 may also be configured to limit the peak current flowing through the load path of the IGBT 102 for each cycle to protect the IGBT 102 from damage due to excessive current or excessive temperature generated by the current flowing through the load path of the IGBT 102. Limiting the current flowing through the IGBT 102 also limits the current flowing through the resonant inductor 106, thereby limiting the maximum voltage across the load path of the IGBT 102 when the resonant capacitor 104 is fully charged.
The AC power source 124 is configured to provide power to the IH cooker system 100. The AC power supply can provide 230VrmsAnd high-line power of 50Hz, or 110VrmsAnd a low-line power of 60 Hz. Other voltages and frequencies may also be used. In various embodiments, the AC power source 124 represents, for example, an AC voltage generator such as a power inverter, or a power grid that provides AC line voltage.
The bridge rectifier 118 is configured to rectify a signal from the AC power source 124. The bridge rectifier 118 is implemented with four diodes. Alternatively, synchronous rectification may be used. Any other fairing mechanism known in the art may also be used.
The temperature sensors 110 and 112 are external temperature sensors configured to monitor temperature and communicate the monitored temperature to an external circuit, such as a controller. The temperature sensors 110 and 112 may be implemented using thermistors. The temperature sensor 112 may be integrated with the IGBT 102. Other embodiments are also possible.
The load 144 is a load to be heated and is typically a cooking vessel. Any load containing material responsive to induction heating can be used.
The resonant tank 105 may be implemented with a resonant inductor 106 and a resonant capacitor 104. Resonant inductor 106 may be implemented with an induction coil. Alternatively, the resonant inductor may be implemented using any inductive element known in the art. The inductance of the resonant inductor 106 and the capacitance of the resonant capacitor 104 may be selected such that the resonant tank 105 resonates at a particular frequency. The frequency may be selected such that the transfer of energy from resonant inductor 106 to load 144 is efficient. Due to tolerances, the type and placement of the load 144 and parasitic impedances may affect the optimum frequency, making resonant tank resonant near the optimum frequency sufficient for efficiency improvement. For example, in a system exhibiting efficient energy transfer to load 144 at a frequency of 24kHz, resonant capacitor 104 may be selected to have a capacitance of 300nF, and resonant inductor 106 may be selected to have an inductance value of 110 μ H. Other values may also be used.
The output block 128 is configured to control the gate of the IGBT 102 via the gate driver 120. Output block 128 may be implemented with input/output (I/O) circuitry, Pulse Width Modulation (PWM) circuitry, digital-to-analog converter (DAC), or with any other implementation known in the art.
The gate driver 120 is configured to control the gate of the IGBT 102. The gate driver 120 may be implemented in an open loop implementation in any manner known in the art. Alternatively, the gate driver 120 may be implemented in a closed loop implementation, such as a voltage regulator. In some embodiments, the gate driver 120 is implemented with an open-loop mode and a closed-loop mode, wherein the modes may be based on the V of the IGBT 102ceTo select. Other implementations are possible.
The user interfaces 140 and 142 are configured to provide and receive information from a user, respectively. The user interface 142 may be implemented with mechanical buttons or a touch interface. Other implementations are possible. The user interface 140 may be a visual display, a speaker, a device capable of providing tactile feedback, a combination thereof, or any other user interface known in the art.
In some embodiments of the invention, the IGBT, the current limiter circuit, the overvoltage protection circuit, and the temperature sensor are integrated in a six-pin package. The protection mechanism operates independently of an external controller and the IGBTs are controllable via control pins, which may also be used to communicate a fault condition of the IGBTs with external circuitry.
FIG. 2a shows a protection IGBT216 in an IH cookware subsystem 200 according to an embodiment of the invention. IH cooker subsystem 200 includes resonant tank 205, protection IGBT216, resistors 208 and 210, sense resistor 212, and capacitor 204. The protection IGBT216 includes the IGBT 202, the temperature sensor 214, a diagnostic block 219, and a protection driver 218.
IH cookware subsystem 200 may receive power through a power supply (not shown) connected to a bridge rectifier (not shown) connected to terminals 220 and 226. During normal operation, a controller (not shown) may turn the IGBTs 202 on and off via control signals 224 to resonate the resonant tank 205 in a manner similar to that described with reference to the IH cooker system 100. For example, an external open drain driver (not shown) may be used to externally control the INN terminal 238 such that when the external open drain driver pulls the INN terminal 238 low, the IGBT 202 turns on, and when the external open drain driver turns off, the INN terminal 238 is pulled high internally and the IGBT 202 turns off. Other implementations for controlling the IGBT 202 are also possible.
The protection driver 218 may control the gate of the IGBT 202 and may protect the IGBT 202 from damage. The protection driver 218 includes six terminals: the C terminal 238 is connected to the collector terminal of the IGBT 202. The E/COM terminal 234 is connected to the emitter terminal of the IGBT 202 and the common terminal (COM)217 of the protection driver 218. The INN terminal 238 is connected to the INN terminal 215 of the protection driver 218 and the diagnostic block 219 and may receive control signals to control whether the IGBT 202 is turned on or off and may provide signals with diagnostic information. The VCC terminal 240 receives power for powering the protected IGBT 216. The CS terminal 236 is used to monitor the current flowing through the load path of the IGBT 216. The VDET terminal 232 is used to monitor the voltage across the load path of the IGBT 202 and may also be used to monitor the voltage between the collector and gate terminals of the IGBT 202. Some embodiments may implement a protection driver 218 with more terminals. Other embodiments may integrate or remove some components in the protection driver 218 to achieve a lower terminal count.
The protection driver 218 may implement a plurality of protection components. For example, the protection driver 218 may include a current limiting mechanism that limits the maximum current flowing through the load path of the IGBT 202. The protection driver 218 may also include overvoltage detection and protection, which may limit the voltage across the load path of the IGBT 202. The protection driver 218 may also include over-temperature protection, which may warn of and/or turn off the IGBT 202 or the protected IGBT216 due to overheating. Some embodiments may configure the protected IGBTs 216 into a low power mode to avoid damage due to overheating.
The diagnostic block 219 is configured to provide diagnostic information regarding the status of the protected IGBTs 216 to an external circuit, such as a controller. The diagnostic information may include whether a fault occurred and, if so, what kind of fault occurred.
The diagnostic block 219 may communicate with external circuitry (not shown) through the INN terminal 238. For example, when an open drain driver external to the INN terminal 238 is controlled to turn off, the diagnostic block may pull up the voltage of the INN terminal 238 to a different voltage depending on whether there is a fault and, if so, pull up the voltage of the INN terminal 238 to a different type of voltage depending on which fault is present. The diagnostic block 219 may communicate with external circuitry in other ways known in the art, for example by using a communication interface such as I2C. SPI, or other protocol.
The protected IGBT216 may be integrated in a single chip, such as a six-pin package. Different numbers of pins may also be used. For example, the protected IGBTs 216 may share a substrate and may be implemented in a monolithic integrated circuit on a single semiconductor substrate. The protected IGBTs 216 may also be implemented in a multi-chip package containing one or more semiconductor dies. Some embodiments may integrate all of the components of the protected IGBT 216. Other embodiments may integrate only some of the components, such as the temperature sensor 214 and the IGBT 202. Still other embodiments may integrate the resonant tank 205 with external resistors and capacitors. A controller circuit providing control signal 224, a bridge rectifier coupled to terminals 220 and 226, and other components may also be integrated.
The temperature sensor 214 is configured to monitor the junction temperature of the IGBT 202. The temperature sensor 214 may be implemented in the same substrate as the IGBT 202 and may be implemented as a diode connected to a circuit that monitors the current flowing through the diode and compares it to a threshold or set of thresholds. Having the temperature sensor 214 implemented in the same substrate of the IGBT 202 has the following advantages: since there is little or no thermal resistance between the temperature sensor and the IGBT 202, a fast response time is exhibited. Alternatively, the temperature sensor 214 may be implemented in a different substrate within the package and may be thermally coupled to the IGBT 202.
As shown in fig. 2a, the IGBT 202 is an n-type transistor. In embodiments of the invention, the IGBT 202 may be implemented using n-type or p-type transistors, including but not limited to IGBTs, silicon carbide (SiC) Junction Field Effect Transistors (JFETs), gallium nitride (GaN) High Electron Mobility Transistors (HEMTs), and power Metal Oxide Semiconductor Field Effect Transistors (MOSFETs). The choice of which transistor to use can be made according to the specifications, current, voltage and power levels of the particular system being designed and the circuitry can be appropriately adjusted to accommodate the particular device type.
Advantages of some embodiments of the invention include: by integrating the temperature sensor 214 with the protection driver 218 and the IGBT 202, the response time to fault conditions is reduced, thereby increasing the robustness of the system. Additional advantages include: the integrated solution can effectively protect the IGBTs 202 without relying on an external controller, which can simplify system design and reduce system cost. Increased integrated solution reliability may also reduce failures in the field.
Fig. 2b shows a high-level view of the protection driver 218 according to an embodiment of the invention. The protection driver 218 includes a gate driver 244, a current limiter circuit 243, an overvoltage protection circuit 241, and an over-temperature protection circuit 245. As shown in fig. 2b, the protection driver 218 further includes a VCC terminal 205, an INN terminal 215, a VDET terminal 213, a GD terminal 209, a CS terminal 207, a Temp terminal 211, and a Com terminal 217. Some embodiments of protection driver 218 may not exhibit physical terminals for terminals 205, 207, 209, 211, 213, 215, and 217. Conversely, terminals 205, 207, 209, 211, 213, 215, and 217 may be discrete nodes. Other embodiments may combine some of the terminals or nodes 205, 207, 209, 211, 213, 215, and 217.
Fig. 2c shows the protection driver 218 of the diagram with the current limiter circuit 243 according to an embodiment of the present invention. Current limiter 243 includes a reference voltage generator 248, a comparator 243, and a logic gate 247. During normal operation, the control signal 224 controls whether the IGBT 202 is turned on or off when the current limiter circuit 243 senses current through the load path of the IGBT 202 via the sense resistor 212. When the current flowing through the load path of the IGBT 202 exceeds a predetermined threshold, the IGBT 202 is turned off independently of the control signal 224. For example, as shown in fig. 2c, comparator 246 is configured to change state when the voltage at node CS exceeds a reference voltage generated by reference voltage generator 248. When the output of comparator 248 is high, gate driver 244 turns IGBT 202 on when the INN terminal is low and turns IGBT 202 off when the INN terminal is high. When the output of the comparator 248 is low, the IGBT 202 is turned off regardless of the voltage at the INN terminal.
A common mode voltage or ground reference to protect the driver 218 is provided by the Com terminal 217. Since the Com terminal 217 is connected to the emitter node of the IGBT 202 and since the current flowing through the load path of the IGBT 202 flows from the collector of the IGBT to the emitter of the IGBT 202 toward the terminal 226 when the IGBT 202 is turned on, the voltage sensed at the node CS may be negative. The voltage sensed at node CS may thus be shifted by a positive voltage (not shown) and then compared by comparator 246 to a positive threshold generated by reference voltage generator 248. For example, the voltage at node CS may be added with an offset voltage of 2.5V and compared to a reference of 2V. Alternatively, the reference voltage generator 248 may generate a negative reference voltage by using, for example, an external negative reference or a negative charge pump. Other implementations are possible.
As shown in fig. 2c, the sense resistor 212 is outside the gate driver loop. In other words, the gate driver 244 is generated as an emitter connected to the IGBT 202The reference GD terminal 209 of the com terminal 217, thereby directly controlling the gate emitter voltage V of the IGBTge. Thus, the gate driver 244 may control V of the IGBT 202 independently of the amount of current flowing through the sense resistor 212geMaking the switching of the IGBT 202 more efficient. Reducing the resistance of the gate driver loop may also result in faster response times for turning on and off the IGBTs 202.
As shown in fig. 2c, logic gate 247 is an AND gate having an inverting input AND a non-inverting input AND comparator 246 is a schmitt trigger comparator. It is to be understood that logic gate 247, comparator 246 and reference voltage generator 248 may be implemented in any manner known in the art.
FIG. 2d shows waveforms of the IH cookware subsystem 200 according to an embodiment of the invention. Curve 250 shows what is also referred to as the collector emitter voltage or VceThe voltage across the load path of the IGBT 202, curve 252 shows the voltage at the CS terminal 207 representing the current through the load path of the IGBT 202, and curve 254 shows the voltage at the INN terminal 215 representing the control signal 224.
As can be seen in curves 254 and 252 and 250, during normal operation, when the voltage of the INN terminal 215 is low, since the IGBT is on, V of the IGBT 202ceIs low and current flows through the load path of the IGBT 202. When the voltage of the INN terminal 215 is high, since the IGBT 202 is turned off, the current stops flowing through the load path of the IGBT, and V of the IGBT 202ceIncreasing and decreasing based on the resonant tank.
As shown in fig. 2d, the higher the peak current of the current flowing through the load path of the IGBT 202 when the IGBT 202 is on, the V of the IGBT 202 when the IGBT 202 is offceThe higher. Thus, limiting the current flowing through the load path of the IGBT 202 for each cycle may also limit the maximum V of the IGBT 202ce。
Fig. 2e and 2f show V of the load path through the IGBT 202 with two different AC input voltages according to an embodiment of the inventionceAnd the waveform of the current. Curve 280 shows V for IGBT 202ceAnd curve 282 shows the cross-over IGBT 202, current of the load path. FIG. 2e shows a graph having 230VrmsThe waveform of the AC input voltage. FIG. 2f shows a cross-section having 260VrmsThe waveform of the AC input voltage. The maximum V of the IGBT 202, as shown by curve 280 in FIGS. 2e and 2fceIs at 1.07kV regardless of the AC input voltage due to the current limit for each cycle.
Fig. 2g shows the protection driver 218 with a diagram of an overvoltage protection circuit 241 according to an embodiment of the invention. Overvoltage protection circuit 241 includes a reference voltage generator 260, a Proportional Integral (PI) controller 266, a comparator 258, inverters 262 and 264, and switches 270 and 272. During normal operation, switch 272 is closed, switch 270 is open, and control signal 224 controls whether IGBT 202 is turned on or off while overvoltage protection circuit 241 monitors the voltage of the collector node of IGBT 202 by monitoring the voltage of VDET terminal 213. The resistors 208 and 210 down-divide the voltage of the collector node of the IGBT 202. Since the resistor 210 is coupled between the VDET terminal 213 and the Com terminal 217, the voltage of the VEDT terminal 213 is also V of the IGBT 202ceIs measured.
When V of IGBT 202ceWhen the voltage exceeds a predetermined threshold, the switch 270 is closed, the switch 272 is opened and the PI controller 266 controls the gate of the IGBT 202 to adjust the voltage to a predetermined target voltage. By adjusting V of IGBT 202ceVoltage, some current flows through the load current of the IGBT 202 without fully discharging the resonant tank 205. It is to be understood that the PI controller 266 may not be able to reset the V of the IGBT 202 when the overvoltage condition is extinguished or sufficient excess energy from the overvoltage condition is dissipatedceAdjusted upward to a predetermined target. However, in this case, it may not be necessary to adjust V of the IGBT 202ceBecause the risk of damaging the IGBT 202 due to an overvoltage condition has been reduced or eliminated.
Fig. 2h shows V of the IGBT 202 during an overvoltage condition according to an embodiment of the inventionceThe current through the load path of the IGBT 202, and the voltage at the gate of the IGBT 202. Curve 280 shows V for IGBT 202ceAnd curve 282 shows the current through the load path of the IGBT 202And a curve 284 shows the voltage of the gate of the IGBT 202. As shown in fig. 2h, even in the event of an overvoltage, the gate of the IGBT 202 is turned on to adjust VceVoltage, thereby clamping the voltage across the load path of the IGBT 202. As shown by curve 282, current flows through the load path of the IGBT 202 during the trimming process. The total energy consumed during the clamping process in the overvoltage event shown in fig. 2h is approximately 500 mJ.
Fig. 2i shows the protected IGBT216 with a diagram of the diagnostic circuit 219 according to an embodiment of the present invention. The diagnostic circuit 219 includes a current source 223 and a programmable reference voltage generator 221. A controller 225 having a transistor 227 in an open drain configuration is connected to the INN terminal 238 to control the IGBT 202. When transistor 227 is turned on, the voltage at INN terminal 238 is at or near zero volts, thereby turning on IGBT 202. When transistor 227 is off, current source 223 pulls the voltage of INN terminal 238 high to the voltage given by programmable reference voltage 221. The current of the current source may be selected such that the current is small enough to be overcome by transistor 227 when transistor 227 is on (over).
The voltage given by the programmable reference voltage generator 221 may depend on whether a fault is present in the protected IGBT216 and the type of fault present. For example, FIG. 2j shows a table with voltage ranges and fault types according to an embodiment of the invention. As shown in fig. 2j, the external circuit may interpret a voltage in the range of 1.25V to 1.75V of the INN terminal 238 as a no fault condition. Similarly, the external circuit may interpret a voltage in the range of 2.5V to 3.3V of the terminal INN as an over-temperature warning, and interpret a voltage below 0.5V of the terminal INN as an over-voltage detection or an over-temperature shutdown. Other voltages may be used and different types of faults may be conveyed via INN terminal 238.
The programmable reference voltage generator 221 may generate voltages according to fig. 2 j. The programmable reference voltage generator 221 may be implemented using a digital-to-analog converter (DAC), or in any other manner known in the art.
The current source 223 may be implemented by a resistor. Other implementations are possible.
Fig. 2k shows a flow chart of an embodiment method 271 of operating an IGBT transistor. The method 271 may be implemented in the IH cooker subsystem 200, but it may also be implemented with other transistor types and in other applications in other ways known in the art. The discussion that follows assumes that the IH cooker subsystem 200 as shown in FIGS. 2a-2j implements a method 271 for operating protected IGBT transistors.
During step 273, a control signal, such as control signal 224, is received. During step 275, it is determined whether the control signal is high or low. Step 275 may be performed each time the control signal transitions from the first state to the second state. Alternatively, step 275 may be polled periodically.
When the control signal is low, step 287 is performed. During step 287, an IGBT, such as IGBT 202, is turned on. During step 289, the current flowing through the load path of the IGBT 202 is monitored. The current may be monitored by using a sense resistor, such as sense resistor 212. Alternatively, other current monitoring techniques may be used, such as by using current mirrors, current converters, and hall sensors. During step 279, the current flowing through the IGBT is compared to a reference. When the magnitude of the current flowing through the IGBT is larger than the reference, step 291 is performed. During step 291, the IGBT is turned off. Step 279 may be performed periodically. Alternatively, step 279 may asynchronously detect an over-current event.
When the control signal is high, step 283 is performed. During step 283, the IGBT is turned off. During step 285, the voltage at the collector node of the IGBT is monitored. The voltage is monitored by using comparators and reference voltage generators, such as comparator 258 and reference voltage generator 260. Alternatively, other voltage monitoring techniques may be used, such as by using an ADC. During step 281, the voltage of the collector node of the IGBT is compared to a reference. When the voltage of the collector node of the IGBT is greater than the reference, step 293 is performed. During step 293, V of IGBTceAdjusted to a target voltage. Step 281 may be performed periodically. Alternatively, step 281 may detect the overvoltage condition asynchronously.
Step 297 may be performed continuously regardless of the state of the control signal. During step 297, the temperature of the IGBT is monitored. The temperature of the IGBT may be sensed by a temperature sensor, such as temperature sensor 214. During step 299, the temperature of the IGBT is compared to a reference. When the temperature of the IGBT is greater than the reference, step 295 is performed. During step 295, the IGBTs may be turned off, the system may be turned off or placed in a low power state, or any other mechanism may be performed to reduce or prevent the temperature from increasing to a temperature that may damage the IGBTs or other system components. Step 299 may be performed periodically. Alternatively, step 299 may detect the over-temperature condition asynchronously.
Alternative implementations of the current limiter circuit are also possible. For example, fig. 3 shows the protection driver 318 of a diagram with a current limiter circuit 343, according to an embodiment of the invention. The current limiter circuit 343 operates in a similar manner to the current limiter circuit 243 and may be implemented in systems that also implement other protection mechanisms such as over-temperature and over-voltage protection circuits. However, the current limiter circuit 343 is implemented with the sense resistor 212 connected between the Com terminal 317 and the emitter node of the IGBT 202, while the CS terminal 307 is connected to the emitter node of the IGBT 202. Other implementations are possible.
Alternative implementations of the overvoltage protection circuit are also possible. For example, fig. 4 shows protection driver 418 with a diagram of overvoltage protection circuit 441 according to an embodiment of the invention. The overvoltage protection circuit 441 operates in a similar manner as the overvoltage protection circuit 241 and may be implemented in systems that also implement other protection mechanisms such as over-temperature and current limiter protection circuits. However, the over-voltage protection circuit 441 implements an Operational Transconductance Amplifier (OTA)402 instead of the PI controller 266. Other implementations are possible.
Fig. 5a shows a protection driver 518 having a diagram of an overvoltage protection circuit 541, according to an embodiment of the invention. The overvoltage protection circuit 541 operates in a similar manner as the overvoltage protection circuit 241 and may be implemented in systems that also implement other protection mechanisms such as ultra-high and current limiter protection circuits. However, the overvoltage protection circuit 541 implements the dynamic reference voltage generator 560 instead of the reference voltage generator 260 and includes the energy calculation block 502.
The dynamic reference voltage generator 560 may dynamically change the regulation target voltage to improve the efficiency of the system. For example, upon detection of an overvoltage condition such as VceAbove 1.1kV, the dynamic reference voltage generator 560 may generate the first reference voltage such that the overvoltage protection circuit 541 will apply the voltage VceTo a first target voltage, such as 1.1 kV. As current flows through the IGBT 202, the IGBT 202 heats up, increasing the breakdown voltage of the IGBT 202 due to the positive thermal coefficient. After a period of time, the breakdown voltage of the IGBT 202 may increase to, for example, 1.3 kV. At this time, the dynamic reference voltage generator 560 may generate the second reference voltage such that the overvoltage protection circuit 541 converts the voltage VceTo a second target voltage, such as 1.3 kV. By increasing V of IGBT 202ceLess current flows through the load path of the IGBT 202, thereby reducing the energy dissipated by the voltage clamping mechanism.
FIG. 5b shows V of the IGBT 202 during an overvoltage condition according to an embodiment of the inventionceThe current through the load path of the IGBT 202, and the gate voltage of the IGBT 202. Curve 580 shows V for IGBT 202ce Curve 582 shows the current through the load path of the IGBT 202 and curve 584 shows the gate voltage of the IGBT 202. As shown in fig. 5b, even in the event of an overvoltage, the IGBT 202 is turned on to turn V on based on the first reference voltage generated by the dynamic reference voltage generator 560ceThe voltage is regulated to a first target voltage of 1.1kV, thereby clamping the voltage across the load path of the IGBT 202. Will VceThe first time after the voltage is adjusted to 1.1kV, the reference voltage generated by dynamic reference voltage generator 560 is increased to adjust VceThe voltage is adjusted to 1.4kV, thereby reducing the gate voltage of the IGBT 202. Since the breakdown voltage of the IGBT 202 increases due to heat generated by the current flowing through the load path of the IGBT 202, the IGBT 202 remains protected. Total dissipated during clamping process in overvoltage event shown in fig. 5bThe energy is about 250mJ, which is about half the energy dissipated in a similar overvoltage event when a fixed clamp voltage is used as shown in fig. 2 h.
Other mechanisms for changing the target clamping/regulation voltage may be used. For example, the target regulation voltage may increase linearly with time. Some embodiments may set the target according to a previously characterized behavior of the breakdown voltage of a particular IGBT. Other embodiments may dynamically change the target regulation voltage based on actively monitoring the junction temperature of the IGBT 202. Other implementations are possible.
Fig. 5c shows a flow chart of an embodiment method 501 of operating an overvoltage protection circuit. The method 501 may be implemented in the protection driver 518, but may also be implemented in other overvoltage protection circuits, other applications, with other transistor types, and in other ways known in the art. The following discussion assumes that the protection driver 518, as shown in fig. 5a, implements the method 501 of operating an overvoltage protection circuit.
During step 503, the voltage at the collector node of an IGBT, such as IGBT 202, is monitored. The voltage may be monitored by using comparators and reference voltage generators, such as comparator 258 and reference voltage generator 560. Alternatively, other voltage monitoring techniques may be used, such as by using an ADC. During step 505, the voltage of the collector node of the IGBT is compared to a reference. When the voltage of the collector node of the IGBT is greater than the reference, step 507 is performed. During step 507, V of IGBTceIs regulated to a first target voltage. During step 509, a wait time elapses. During step 511, V of IGBTceIs regulated to a second target voltage. The second target voltage may be greater than the first target voltage. Having the second target voltage greater than the first target voltage allows for reduced power dissipation during the clamping process while still protecting the IGBTs.
Fig. 5d shows a flow chart of an embodiment method 513 of operating an overvoltage protection circuit. Method 513 may be implemented in protection driver 518, but may also be implemented in other overvoltage protection circuits, in other applications, with other transistor types, and in other ways known in the art. The following discussion assumes that the protection driver 518, as shown in fig. 5a, implements a method 513 of operating an overvoltage protection circuit.
During step 515, the voltage at the collector node of the IGBT, such as IGBT 202, is monitored. The voltage may be monitored by using comparators and reference voltage generators, such as comparator 258 and reference voltage generator 560. Alternatively, other voltage monitoring techniques may be used, such as by using an ADC. During step 517, the voltage of the collector node of the IGBT is compared to a reference. When the voltage of the collector node of the IGBT is greater than the reference, step 519 is performed. During step 519, V of IGBTceIs dynamically adjusted. For example, the regulated voltage may be increased linearly to reduce power dissipation during the clamping process. Some embodiments may perform real-time energy calculations, for example, using energy calculation block 502, and determine the adjustment voltage based on the calculated energy. Other embodiments may vary the regulation voltage according to an arbitrary curve. An arbitrary curve can be obtained, for example, by characterizing the breakdown voltage of the IGBT at different temperatures. Other regulated voltages are also possible.
FIG. 6 shows a protected IGBT 616 in an IH cookware subsystem 600, according to an embodiment of the invention. The protected IGBT 616 operates in a similar manner as the protected IGBT 216. However, the protected IGBT 616 is integrated with resistors 608 and 610, a sense resistor 612, and also includes a power supply 604 to provide power to a protection driver 618. Accordingly, the protected IGBT 616 may be integrated in a conventional transistor package, such as a conventional 3-pin package.
It is possible to detect when a load such as a cooking vessel is removed from the cooking surface. For example, FIG. 7a shows a protection driver 718 in an IH cookware subsystem 700 in accordance with an embodiment of the invention. The protection driver 718 operates in a similar manner as the protection driver 218. However, protection driver 718 includes a removal detection circuit 745 for detecting when load 144 is removed from the cooking surface.
Detecting that load 144 has been removed from the cooking surface may be accomplished by monitoring the current I flowing through diode 750senseTo make sureNow. During normal operation, the current flowing through diode 750 is very small or zero. For example, when the load 144 is near the cooking surface and the IGBT 202 is on, current generally flows through the load path of the IGBT 202 to ground. When the IGBT 202 is turned off, the diode 750 is typically reverse biased and will therefore exhibit little or no current. When the load 144 is removed from the cooking surface, the load is no longer proximate to the resonant inductor 206. When the IGBT 202 is turned off with the load 144 removed from the cooking surface, little or no energy will be transferred from the resonant inductor 206 to the load 144. Thus, prior to removing the load 144 from the cooking surface, the capacitor 204 may be charged to a higher peak voltage compared to the peak voltage of the resonant capacitor 204. The higher voltage of the resonant capacitor 204 may cause the current flowing through the resonant inductor 206 when the capacitor 708 is charged to be higher than before the load 144 is removed from the cooking surface. Thus, diode 750 may be forward biased by removing load 144 from the cooking surface, thereby conducting current.
The current I flowing through the diode 750 may be sensed by measuring the voltage across the sense resistor 212sense. A comparator 746 may be used to compare the voltage sensed at the CS terminal 207 with a reference voltage generated by a reference voltage generator 748. The comparator 746 effectively senses the voltage across the sense resistor 212 because the comparator 746 is referenced to the Com terminal 217. When the sensed current is above a first threshold, such as 50A, a load removal event is detected. Based on the load removal event, the IGBT 202 may be turned off. Other actions may be taken upon detection of a removal event.
The threshold current for detecting load removal may vary, for example, based on the size of the load, the material, the amount of power transferred to the load, and the distance between the load and the resonant inductor. It will be appreciated that the threshold may be adjusted to other current values, for example 20A or 100A. The threshold current for detecting load removal may also be dynamically adjusted. For example, a lower threshold current may be used when low power is being delivered to the load 144.
FIGS. 7b and 7c show embodiments according to the inventionBefore and after the cooking vessel is removed from the PCB arrangement simulating the cooking surface, a single pulse waveform of current flowing through diode 750. In particular, the waveforms of fig. 7b and 7c relate to an embodiment in which the PCB arrangement of the simulated cooking surface delivers an output power of 2.1kW at a switching frequency of 20 kHz. The cooking vessel is a stainless steel kettle. The current scale of fig. 7b and 7c is 50A per minute. Curve 705 shows V for IGBT 202ceAnd (5) displaying. Curve 709 shows the current flowing through diode 750. Curves 709 and 710 show the maximum peak current of diode 750 before and after, respectively, removing the cooking vessel from the cooking surface.
As shown in fig. 7b and 7c, the peak current flowing through the diode 750 greatly increases after the cooking container is removed. For example, as shown by curve 709, the peak current flowing through diode 750 before the cooking vessel is removed reaches approximately 20A. As shown by curve 710, the peak current flowing through diode 750 after the cooking vessel is removed reaches about 90A.
Fig. 7d shows a scaled down version of the current flowing through the diode 750 before and after the cooking container is removed from the cooking surface, according to an embodiment of the invention. In particular, the waveforms of fig. 7b and 7c relate to embodiments where the cooktop system delivers 2.1kW of output power at a switching frequency of 20 kHz. The cooking vessel is a stainless steel kettle. The current scale of fig. 7d is 20A per minute. As shown in fig. 7d, at time t0The cooking vessel is removed from the cooking surface. At this point, the peak current through diode 750 begins to increase as shown by curve 707.
Example embodiments of the present invention are summarized herein. Other embodiments may also be understood from the specification and claims as filed in their entirety.
Example 1 a method of operating a transistor, comprising: turning on and off the transistor based on a control signal; monitoring a voltage of a collector node of the transistor; detecting whether a voltage of a collector node of the transistor is greater than a first threshold; and adjusting a voltage across a load path of the transistor to a first target voltage after detecting that the voltage of the collector node of the transistor is greater than the first threshold.
Example 2. the method of example 1, wherein adjusting the voltage across the load path of the transistor comprises: monitoring a voltage of a collector node of the transistor; and adjusting a voltage across a load path of the transistor based on the monitored voltage of the collector node of the transistor.
Example 3. the method of one of examples 1 or 2, wherein the transistor comprises an Insulated Gate Bipolar Transistor (IGBT).
Example 4. the method of one of examples 1 to 3, further comprising: adjusting a voltage across a load path of the transistor to a second target voltage after a first period when the voltage of the collector node of the transistor is detected to be greater than the first threshold.
Example 5. the method of one of examples 1 to 4, further comprising: monitoring a current flowing through a load path of the transistor; and turning off the transistor when a current flowing through a load path of the transistor is greater than a second threshold.
Example 6. the method of one of examples 1 to 5, wherein turning the transistor on and off further comprises: receiving the control signal at a control terminal; turning on the transistor when the voltage of the control terminal is below a second threshold; and pulling the control terminal high to a first voltage when the control terminal is floating.
Example 7. the method of one of examples 1 to 6, further comprising: determining whether a fault condition occurs in the transistor; and determining the first voltage based on whether a fault condition has occurred.
Example 8. the method of one of examples 1 to 7, further comprising: the cooking vessel is heated by turning the transistor on and off.
Example 9. the method of one of examples 1 to 8, further comprising: monitoring a diode current flowing through a diode coupled across a load path of the transistor; and detecting a removal event when the diode current is greater than a predetermined diode current threshold.
Example 10. a circuit including a protection driver, comprising: a gate driver configured to be coupled to a transistor and configured to turn the transistor on and off based on a control signal; an overvoltage detection circuit configured to monitor a voltage of a collector node of the transistor, detect whether the voltage of the collector node of the transistor is greater than a first threshold; and a regulator circuit configured to regulate a voltage across a load path of the transistor to a first target voltage after the overvoltage detection circuit detects that the voltage of the collector node of the transistor is greater than the first threshold.
Example 11. the circuit of example 10, wherein the regulator circuit regulates a voltage across the load path of the transistor based on the monitored voltage of the collector node of the transistor.
Example 12 the circuit of one of examples 10 or 11, further comprising the transistor.
Example 13. the circuit of one of examples 9 to 12, wherein the transistor comprises an Insulated Gate Bipolar Transistor (IGBT).
Example 14. the circuit of one of examples 9 to 13, further comprising an inductive coil coupled to a load path of the transistor.
Example 15. the circuit of one of examples 9 to 14, wherein the regulator circuit is further configured to: adjusting a voltage across a load path of the transistor to a second target voltage after a first period when the overvoltage detection circuit detects that the voltage of the collector node of the transistor is greater than the first threshold.
Example 16. the circuit of one of examples 9 to 15, wherein the second target voltage is higher than the first target voltage.
Example 17. the circuit of one of examples 9 to 16, wherein the protection driver further comprises a current limiter circuit configured to turn off the transistor when a current flowing through a load path of the transistor has a magnitude greater than a second threshold.
Example 18. the circuit of one of examples 9 to 17, wherein the current limiter circuit includes a comparator having a first input coupled to a reference voltage and a second input coupled to the emitter node of the transistor via a sense resistor; and the protection driver has a common reference node coupled to an intermediate node coupled between the sense resistor and the emitter node of the transistor.
Example 19. the circuit of one of examples 9 to 17, wherein the limiter circuit includes a comparator having a first input coupled to a positive reference voltage and a second input coupled to an emitter node of the transistor; and the protection driver has a common reference node coupled to the emitter node of the transistor via a sense resistor.
Example 20 an integrated circuit, comprising: insulated Gate Bipolar Transistors (IGBTs); a temperature sensor; and a protection driver including a gate driver coupled to the gate of the IGBT, a current limiter circuit coupled to the gate driver, and an overvoltage protection circuit coupled to the gate of the IGBT.
Example 21. the integrated circuit of example 20, wherein the integrated circuit is packaged in a 6-pin package.
Example 22. the integrated circuit of example 20, wherein the integrated circuit is packaged in a 3-pin package.
Example 23. the integrated circuit of one of examples 19 to 22, further comprising diagnostic circuitry configured to: applying a first voltage to an input pin when the IGBT is turned off and no fault is detected, and applying a second voltage to the input pin when the IGBT is turned off and a fault is detected, wherein the input pin is coupled to the gate driver, the second voltage being different from the first voltage.
Example 24 the integrated circuit of one of examples 19 to 23, wherein the overvoltage protection circuit comprises: a first comparator having a first input coupled to a first reference voltage and a second input coupled to a collector node of the IGBT; a first switch coupled between an output of the gate driver and a gate of the IGBT; a regulation circuit configured to regulate a voltage of the collector node to a target collector voltage and coupled between the collector node of the IGBT and the gate of the IGBT; and a second switch coupled between the regulating circuit and the gate of the IGBT, wherein the first switch is configured to turn off when the output of the first comparator is in a first state, and the second switch is configured to turn on when the output of the first comparator is in the first state.
Example 25 the integrated circuit of one of examples 19 to 24, wherein the adjustment circuit includes a proportional-integral (PI) controller.
Example 26. the integrated circuit of one of examples 19 to 24, wherein the adjustment circuit comprises an Operational Transconductance Amplifier (OTA).
Example 27. the integrated circuit of one of examples 19 to 26, wherein the target collector voltage is based on a voltage generated by a reference voltage generator.
Example 28 the integrated circuit of one of examples 19 to 27, wherein the reference voltage generator generates a first voltage when an overvoltage condition is detected and generates a second voltage after a first period when the overvoltage condition is detected.
Example 29 the integrated circuit of one of examples 19 to 28, wherein the second voltage is higher than the first voltage.
Example 30 the integrated circuit of one of examples 19 to 29, wherein the current limiter circuit includes a second comparator having a first input coupled to a second reference voltage, a second input configured to be coupled to the emitter node of the IGBT via a sense resistor, and an output coupled to the gate driver.
Example 31 the integrated circuit of one of examples 19 to 30, further comprising the sense resistor.
Example 32 the integrated circuit of one of examples 19 to 31, wherein the current limiter circuit comprises: a first comparator configured to sense current flowing through a load path of the IGBT, the first comparator configured to turn off the IGBT when the sensed current is greater than a predetermined threshold.
While the invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is therefore intended that the appended claims cover any such modifications or embodiments.

Claims (28)

1. A method of operating a transistor, comprising:
turning on and off the transistor based on a control signal;
monitoring a voltage of a collector node of the transistor;
detecting whether a voltage of a collector node of the transistor is greater than a first threshold;
adjusting a voltage across a load path of the transistor to a first target voltage after detecting that a voltage of a collector node of the transistor is greater than the first threshold; and
adjusting a voltage across a load path of the transistor to a second target voltage after a first period when the voltage of the collector node of the transistor is detected to be greater than the first threshold.
2. The method of claim 1, wherein regulating the voltage across the load path of the transistor comprises:
monitoring a voltage of a collector node of the transistor; and
adjusting a voltage across a load path of the transistor based on the monitored voltage of the collector node of the transistor.
3. The method of claim 1, wherein the transistor comprises an Insulated Gate Bipolar Transistor (IGBT).
4. The method of claim 1, further comprising:
monitoring a current flowing through a load path of the transistor; and is
Turning off the transistor when a current flowing through a load path of the transistor is greater than a second threshold.
5. The method of claim 1, wherein turning on and off the transistor further comprises:
receiving the control signal at a control terminal;
turning on the transistor when the voltage of the control terminal is lower than a second threshold; and
pulling the control terminal high to a first voltage when the control terminal is floating.
6. The method of claim 5, further comprising:
determining whether a fault condition occurs in the transistor; and is
The first voltage is determined based on whether a fault condition has occurred.
7. The method of claim 1, further comprising: the cooking vessel is heated by turning the transistor on and off.
8. The method of claim 1, further comprising:
monitoring a diode current flowing through a diode coupled across a load path of the transistor; and is
A load removal event is detected when the diode current is greater than a predetermined diode current threshold.
9. A circuit comprising a protection driver, the protection driver comprising:
a gate driver configured to be coupled to a transistor and configured to turn the transistor on and off based on a control signal;
an overvoltage detection circuit configured to:
monitoring a voltage of a collector node of the transistor;
detecting whether a voltage of a collector node of the transistor is greater than a first threshold; and
a regulator circuit configured to:
adjusting a voltage across a load path of the transistor to a first target voltage after the overvoltage detection circuit detects that the voltage of the collector node of the transistor is greater than the first threshold, an
Adjusting a voltage across a load path of the transistor to a second target voltage after a first period when the overvoltage detection circuit detects that the voltage of the collector node of the transistor is greater than the first threshold.
10. The circuit of claim 9, wherein the regulator circuit adjusts a voltage across a load path of the transistor based on the monitored voltage of the collector node of the transistor.
11. The circuit of claim 9, further comprising the transistor.
12. The circuit of claim 11, wherein the transistor comprises an Insulated Gate Bipolar Transistor (IGBT).
13. The circuit of claim 12, further comprising an inductive coil coupled to a load path of the transistor.
14. The circuit of claim 9, wherein the second target voltage is higher than the first target voltage.
15. The circuit of claim 9, wherein the protection driver further comprises a current limiter circuit configured to turn off the transistor when a current flowing through a load path of the transistor has a magnitude greater than a second threshold.
16. The circuit of claim 15, wherein,
the current limiter circuit includes a comparator having a first input coupled to a reference voltage and a second input coupled to an emitter node of the transistor via a sense resistor; and is
The protection driver has a common reference node coupled to an intermediate node coupled between the sense resistor and an emitter node of the transistor.
17. The circuit of claim 15, wherein,
the current limiter circuit includes a comparator having a first input coupled to a positive reference voltage and a second input coupled to an emitter node of the transistor; and is
The protection driver has a common reference node coupled to the emitter node of the transistor via a sense resistor.
18. An integrated circuit, comprising:
an Insulated Gate Bipolar Transistor (IGBT);
a temperature sensor; and
a protection driver, comprising:
a gate driver coupled to the gate of the IGBT,
a current limiter circuit coupled to the gate driver; and
an overvoltage protection circuit coupled to the gate of the IGBT,
wherein the overvoltage protection circuit comprises a regulation circuit coupled between a collector node and a gate of the IGBT and configured to regulate a voltage of the collector node to a target collector voltage, an
Wherein the target collector voltage is based on a voltage generated by a reference voltage generator that generates a first voltage if an overvoltage condition is detected and a second voltage after a first period when the overvoltage condition is detected.
19. The integrated circuit of claim 18, wherein the integrated circuit is packaged in a 6-pin package.
20. The integrated circuit of claim 18, wherein the integrated circuit is packaged in a 3-pin package.
21. The integrated circuit of claim 18, further comprising a diagnostic circuit configured to:
applying a first voltage to an input pin when the IGBT is turned off and no fault is detected, an
Applying a second voltage to the input pin when the IGBT is turned off and a fault is detected,
wherein the input pin is coupled to the gate driver, and the second voltage is different from the first voltage.
22. The integrated circuit of claim 18, wherein the overvoltage protection circuit further comprises:
a first comparator having a first input coupled to a first reference voltage and a second input coupled to a collector node of the IGBT;
a first switch coupled between an output of the gate driver and a gate of the IGBT; and
a second switch coupled between the regulating circuit and the gate of the IGBT, wherein,
the first switch is configured to turn off when the output of the first comparator is in a first state, an
The second switch is configured to conduct when the output of the first comparator is in the first state.
23. The integrated circuit of claim 18, wherein the regulation circuit comprises a proportional-integral (PI) controller.
24. The integrated circuit of claim 18, wherein the regulating circuit comprises an Operational Transconductance Amplifier (OTA).
25. The integrated circuit of claim 18, wherein the second voltage is higher than the first voltage.
26. The integrated circuit of claim 22, wherein the current limiter circuit comprises a second comparator having a first input coupled to a second reference voltage, a second input configured to be coupled to the emitter node of the IGBT via a sense resistor, and an output coupled to the gate driver.
27. The integrated circuit of claim 26, further comprising the sense resistor.
28. The integrated circuit of claim 18, wherein the current limiter circuit comprises a first comparator configured to sense current flowing through a load path of the IGBT, the first comparator configured to turn off the IGBT when the sensed current is greater than a predetermined threshold.
CN201810218365.XA 2017-03-16 2018-03-16 Method of operating a transistor, circuit comprising a protection driver and integrated circuit Active CN108633118B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US15/460,938 US10728960B2 (en) 2017-03-16 2017-03-16 Transistor with integrated active protection
US15/460,938 2017-03-16

Publications (2)

Publication Number Publication Date
CN108633118A CN108633118A (en) 2018-10-09
CN108633118B true CN108633118B (en) 2021-05-11

Family

ID=63520479

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810218365.XA Active CN108633118B (en) 2017-03-16 2018-03-16 Method of operating a transistor, circuit comprising a protection driver and integrated circuit

Country Status (3)

Country Link
US (2) US10728960B2 (en)
CN (1) CN108633118B (en)
DE (1) DE102018106031A1 (en)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6610468B2 (en) * 2016-08-26 2019-11-27 株式会社デンソー Semiconductor device
US10411692B2 (en) 2016-11-23 2019-09-10 Alpha And Omega Semiconductor Incorporated Active clamp overvoltage protection for switching power device
US10477626B2 (en) 2016-11-23 2019-11-12 Alpha And Omega Semiconductor (Cayman) Ltd. Hard switching disable for switching power device
US10476494B2 (en) 2017-03-20 2019-11-12 Alpha And Omega Semiconductor (Cayman) Ltd. Intelligent power modules for resonant converters
US10644581B2 (en) * 2017-11-01 2020-05-05 Texas Instruments Incorporated DC-DC power conversion circuitry with efficiency optimization using temperature sensing
US11018129B2 (en) * 2018-09-10 2021-05-25 Semiconductor Components Industries, Llc Circuit that changes voltage of back electrode of transistor based on error condition
CN109617505B (en) * 2018-11-21 2020-04-10 北京精密机电控制设备研究所 Intelligent high-power aerospace servo motor driver health management method
US11368150B2 (en) * 2019-01-17 2022-06-21 Texas Instruments Incorporated Reliabtility monitor for field effect transistor devices
CN109994145B (en) * 2019-03-20 2020-12-08 浙江大学 Heat production time extraction method of metal insulation layer metal structure
JP7325314B2 (en) * 2019-12-12 2023-08-14 三菱電機株式会社 semiconductor equipment
CN111082676B (en) * 2019-12-30 2021-04-23 杭州士兰微电子股份有限公司 Switching power supply and control circuit and control method thereof
CN112601338B (en) * 2020-12-10 2023-03-14 宁波公牛光电科技有限公司 Lamp and regulating and controlling circuit thereof

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4937697A (en) * 1989-05-22 1990-06-26 Motorola, Inc. Semiconductor device protection circuit
CN101656528A (en) * 2008-08-19 2010-02-24 恩益禧电子股份有限公司 Semiconductor switch control device
CN102694531A (en) * 2011-03-24 2012-09-26 株式会社电装 Load drive apparatus and semiconductor switching device drive apparatus
CN202696560U (en) * 2012-07-09 2013-01-23 佛山市柏克新能科技股份有限公司 IGBT (insulated gate bipolar translator) driving protection circuit
CN102970009A (en) * 2011-08-31 2013-03-13 瑞萨电子株式会社 Semiconductor integrated circuit and drive apparatus including the same
CN103368160A (en) * 2012-03-28 2013-10-23 英飞凌科技股份有限公司 Clamping circuit
CN103973277A (en) * 2013-02-05 2014-08-06 通用电气公司 Short circuit protection circuit and method for insulated gate bipolar transistor
CN104597356A (en) * 2015-01-30 2015-05-06 广东美的厨房电器制造有限公司 Cookware detection method and device used for cooking utensil
CN204597470U (en) * 2014-11-21 2015-08-26 英飞凌科技股份有限公司 For reducing the circuit arrangement of overvoltage
CN105262468A (en) * 2015-11-03 2016-01-20 佛山市南海区联合广东新光源产业创新中心 IGBT protection and drive circuit
CN105337597A (en) * 2014-08-05 2016-02-17 株式会社电装 Drive circuit for semiconductor switching element and semiconductor switching element module having the same
CN105991010A (en) * 2015-03-23 2016-10-05 英飞凌科技股份有限公司 Verification of gate driver protection logic
CN205657421U (en) * 2016-05-23 2016-10-19 佛山市顺德区美的电热电器制造有限公司 Electromagnetic heating system and voltage surge protection device thereof
CN106160438A (en) * 2015-05-13 2016-11-23 英飞凌科技奥地利有限公司 The Method and circuits of punching is crossed for reducing the collector emitter voltage in igbt

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4480201A (en) * 1982-06-21 1984-10-30 Eaton Corporation Dual mode power transistor
JPH0683042B2 (en) * 1986-03-31 1994-10-19 株式会社東芝 Output driver circuit
DE4142666C2 (en) * 1991-12-21 1996-02-08 Vdo Schindling Circuit arrangement with a semiconductor switch for switching a load
US6947272B2 (en) * 2001-11-20 2005-09-20 Texas Instruments Incorporated Inrush current control method using a dual current limit power switch
JP3791400B2 (en) * 2001-11-22 2006-06-28 三菱電機株式会社 Semiconductor device
US6985343B2 (en) * 2002-04-19 2006-01-10 Daimlerchrysler Corporation Programmable power management switch
JP4196820B2 (en) * 2003-12-18 2008-12-17 株式会社デンソー Ignition device
GB2453447A (en) * 2007-04-27 2009-04-08 Cambridge Semiconductor Ltd A protection scheme for a switched-mode power converter
US7929266B2 (en) 2007-12-19 2011-04-19 Freescale Semiconductor, Inc. Electronic device operable to protect a power transistor when used in conjunction with a transformer
US8279631B2 (en) 2008-08-05 2012-10-02 Active-Semi, Inc. Limiting primary peak charge to control output current of a flyback converter
CN102369654B (en) 2009-03-13 2014-04-02 富士电机株式会社 Switching power supply device, integrated circuit, and method for setting operation state of switching power supply device
JP5724730B2 (en) * 2010-12-14 2015-05-27 富士電機株式会社 Semiconductor device driving apparatus
JP5430608B2 (en) * 2011-04-27 2014-03-05 カルソニックカンセイ株式会社 Semiconductor switching element drive circuit
US9578692B2 (en) 2012-04-19 2017-02-21 Infineon Technologies Americas Corp. Power converter with tank circuit and over-voltage protection
US9048831B2 (en) * 2012-07-13 2015-06-02 General Electric Company Systems and methods for regulating semiconductor devices
US8885310B2 (en) * 2012-10-31 2014-11-11 Freescale Semiconductor, Inc. Gate driver with desaturation detection and active clamping
US9755425B2 (en) * 2014-03-28 2017-09-05 Infineon Technologies Ag Power switch device
US10411692B2 (en) * 2016-11-23 2019-09-10 Alpha And Omega Semiconductor Incorporated Active clamp overvoltage protection for switching power device

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4937697A (en) * 1989-05-22 1990-06-26 Motorola, Inc. Semiconductor device protection circuit
CN101656528A (en) * 2008-08-19 2010-02-24 恩益禧电子股份有限公司 Semiconductor switch control device
CN102694531A (en) * 2011-03-24 2012-09-26 株式会社电装 Load drive apparatus and semiconductor switching device drive apparatus
CN102970009A (en) * 2011-08-31 2013-03-13 瑞萨电子株式会社 Semiconductor integrated circuit and drive apparatus including the same
CN103368160A (en) * 2012-03-28 2013-10-23 英飞凌科技股份有限公司 Clamping circuit
CN202696560U (en) * 2012-07-09 2013-01-23 佛山市柏克新能科技股份有限公司 IGBT (insulated gate bipolar translator) driving protection circuit
CN103973277A (en) * 2013-02-05 2014-08-06 通用电气公司 Short circuit protection circuit and method for insulated gate bipolar transistor
CN105337597A (en) * 2014-08-05 2016-02-17 株式会社电装 Drive circuit for semiconductor switching element and semiconductor switching element module having the same
CN204597470U (en) * 2014-11-21 2015-08-26 英飞凌科技股份有限公司 For reducing the circuit arrangement of overvoltage
CN104597356A (en) * 2015-01-30 2015-05-06 广东美的厨房电器制造有限公司 Cookware detection method and device used for cooking utensil
CN105991010A (en) * 2015-03-23 2016-10-05 英飞凌科技股份有限公司 Verification of gate driver protection logic
CN106160438A (en) * 2015-05-13 2016-11-23 英飞凌科技奥地利有限公司 The Method and circuits of punching is crossed for reducing the collector emitter voltage in igbt
CN105262468A (en) * 2015-11-03 2016-01-20 佛山市南海区联合广东新光源产业创新中心 IGBT protection and drive circuit
CN205657421U (en) * 2016-05-23 2016-10-19 佛山市顺德区美的电热电器制造有限公司 Electromagnetic heating system and voltage surge protection device thereof

Also Published As

Publication number Publication date
DE102018106031A1 (en) 2019-01-24
US10728960B2 (en) 2020-07-28
US20200337122A1 (en) 2020-10-22
CN108633118A (en) 2018-10-09
US20180270913A1 (en) 2018-09-20
US11388784B2 (en) 2022-07-12

Similar Documents

Publication Publication Date Title
CN108633118B (en) Method of operating a transistor, circuit comprising a protection driver and integrated circuit
US9166499B2 (en) Electronic circuit operating based on isolated switching power source
TWI501533B (en) An off-line voltage regulator, off-line regulator integrated circuit and voltage convert method thereof
US10468969B2 (en) Electronic circuit and method for operating an electronic circuit
CN102447406B (en) Alternating current (AC)/direct current (DC) converter
KR20040041201A (en) power supply apparatus for motor and controlling method thereof
WO2014019860A2 (en) Overload limitation in peak power operation
KR100550162B1 (en) Induction heating apparatus using digital signal processor
CN115603559B (en) High-frequency isolation pulse power supply device and control method
JP4294928B2 (en) Stabilized power supply
JP6559343B2 (en) Switching power supply circuit
WO2022204948A1 (en) Apparatus configured to receive power from power supply
WO2008155719A1 (en) Ac / dc converter which regulates the output voltage and prevents the load from current spikes
CN204141641U (en) Electricity cooking pot and controller for heat sink thereof
EP3029471B1 (en) A switched mode power supply circuit
JP3231935B2 (en) Inverter power supply
JP7443578B2 (en) Rectifiers, energy supply devices and systems
JP6832810B2 (en) Power converter
TWI474592B (en) Bypass apparatus for negative temperature coefficient thermistor
TWI830419B (en) Power converter system, control system comprising the same and method of converting power
CN115864869A (en) Control circuit and method for AC/DC conversion and power supply device
CN112313867A (en) Improved induction heating circuit, protection circuit and cooling system for appliances
De Falco et al. Innovative protection concept for single-ended parallel resonant induction heaters
KR20150136875A (en) Power Supply Device
KR20200067030A (en) Power conversion apparatus of detecting hardware fault

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant